latest DNG converter does not work for older systems than MacOSX Catalina

[kers]

problem... Adobe writes about its DNG converter:

What if I own an older version of Photoshop or Lightroom?
You do not have to buy a new version of Photoshop or Lightroom just to get the latest camera support.
Adobe provides backward compatibility for the latest cameras for free in Photoshop CS, CS2, CS3, CS4, CS5, and CS6 as well as Lightroom 1, 2, 3, 4, 5 and 6, through the Adobe DNG Converter. With this tool, you can easily convert camera-specific raw files from supported cameras to a more universal DNG raw file.

https://helpx.adobe.com/camera-raw/kb/why-is-my-camera-not-supported.html

However they just lanched a DNG-converter that needs OSX10.15  or later, but
How can you run older software on macOSX 10.15 Catalina and newer?

I wanted to have support for the Z9 Raw files on OSX 10.14 Mojave but it is not availabkle- not in LR 10,  but also not in the latest DNG-converter that runs on 10.14.
OSX 10.14 is introduced  only 4.5 years ago.
There goes one major benefit of the DNG.
The DNG-converter should run on older systems and provide support for the latest cameras !

[digitaldog]

The latest version of the DNG converter will run on Catalina and later.
You should address your concerns about older support here:
https://community.adobe.com/t5/lightroom-classic/ct-p/ct-lightroom-classic?page=1&sort=latest_replies&filter=all&lang=all&tabid=discussions

The big issue of course is that (in your case), Nikon once again like most camera manufacturers produced a new, slightly differing proprietary raw (unlike the camera JPEG) forcing every new raw converter software company to jump through hoops to support it, via DNG or directly.
And of course, with all the money you spent on a new proprietary raw, you can also fix this issue by using a modern version of Photoshop, Lightroom Classic or another 3rd party raw converter. Expecting support for really old software isn't going to get a lot of sympathies or a fix. 

The DNG-converter should run on older systems and provide support for the latest cameras!

And how far back should this support go, to Photoshop 7 when ACR was introduced, in 2003?

[kers]

I think the big issue is that developers have a problem to support Mojave and the silicon systems at the same time...
and they don't want to spend more time and money on it than necessary...
Nikon or any other company has as much right to innovate as Apple and Adobe does...
In this case Nikon wanted to have a smaller NEF to accommodate the 20 frames/second shooters that we find alongside the sportsfields (to be able to go from 20MP to 45MP)
So anyway i have to say goodbye to old but good ( even better) 32bit software and move on.

Adobe can change the 8? years old text into;
 "you need OSX 10.15 to use the DNG converter and get support for the cameras introduced later than 2020"

And how far back should this support go, to Photoshop 7 when ACR was introduced, in 2003?

the DNG converter...
between 2003 and 2018 Mojave is 15 years... i think 10 years would be OK to keep everybody happy...so 2012- 10.8 Mountain Lion
Than you can still use the CS6 programs that run with 10.11 (2015) with the latest camera's because of DNG support.
That would be nice.

[Chris Kern]

Expecting support for really old software isn't going to get a lot of sympathies or a fix. 

If a fix even is possible.  It's been quite a few years since I wrote any software to run on MacOS, so this is speculation.  But as far as I know Apple tends to stop supporting the link libraries most complex applications rely on after a few major operating system releases: three, if memory serves.  If the operating system support isn't there for a library a software product depends on, there's nothing much the application developer can do about it.  Consumer end-users (i.e., all of us) generally need to stay reasonably current with application software if they want to preserve functionality.

It's different in the enterprise market, where long-term backward compatibility is still the rule.  Or at least I presume it is.  I haven't been involved in that segment of the market for quite a while, either.

. . . you can also fix this issue by using a modern version of Photoshop, Lightroom Classic or another 3rd party raw converter.

Yes.  That's the obvious, and reasonable, solution to issues like this.

[jrp]

One reason that the Mac OS upgrades are free is to encourage people to update, to ease the task for developers. Windows used to be almost fully backwards compatible in theory, although there have always been glitches in practice. All that said, Apple seem to support reasonably old devices with new OS’ (eg, my 2013 Mac Pro), so if your device is older than that, you may have to put your hand in your pocket and get something newer.